Electrical properties of networks of aligned carbon nanotube sheets in liquid crystals

M. Murali, H. Agha, D. Suh, G. Scalia
University of Luxembourg,
Luxembourg

Keywords: carbon nanotube sheets, MWCNT, liquid crystals, resistance

Summary:

Carbon nanotubes (CNTs) are highly electrically conductive and anisotropic nanoparticles that, when physically connected, form networks themselves conductive but at macroscopic scale. Liquid crystals(LC) can impose orientational order on isolated CNTs but they can even impose some degree of orientational order onto networks of nanotubes. In order to explore the properties of CNT networks embedded in LCs, we present here investigations of the electrical properties of aligned multi walled CNT sheets. Electrical resistivity is a basic material property that quantifies opposition of a material to current flow and it can affect the characteristics of a device, such as the series resistance, threshold voltage, RC time constant, and other parameters. One of the most common ways of measuring the resistivity of conductive, thin and flat materials is using a four-point collinear probe. The four-point probe technique involves bringing four probes in contact with a material of unknown resistance, measuring either current or voltage from inner electrodes while applying voltage or current onto external contacts. In this study, we have evaluated the resistance of aligned CNT sheets deposited on glass for different electrode distances. The resistance of the CNT sheets is measured initially using a two-wire configuration and then with four-wire configuration. We also report the effect of the presence of embedding liquid crystal on the resistance of CNTs.